Internal bore gauge



March 23, 194s. A. EISELE 2,438,274

INTERNAL BORE GAUGE Filed Oct. 19, 1945 53 Zw 5639 23 ze 1li 55 3g 10 3 xxxxx y y xx x Patented Mar. 23,1948

UNITED STATES ATENT OFFICE INTERNAL BORE GAUGE Andrew Eisele, Detroit, Mich.

Application October 19, 1945,*Serial No. 623,199

4 Claims. (C1. 33-178) This invention relates to gauges, and in particular, to internal gauges of the dial indicator type.

One object of this invention is to provide lan improved internal bore dial indicator gauge which is conveniently manipulated by one hand of the operator and which will be substantially self-adjusting to the bore which it is intended to measure.

Another object is to provide an internal bore dial indicator gauge wherein the motion of the movable measuring plunger is transmitted to the dial indicator by an improved mechanism which minimizes mechanical errors.

Another object is to provide an internal bore dial indicator gauge wherein the locating pins are arranged with their axes forming an acute angle, thereby enabling them to be mounted in a relatively small and compact holder or casing while possessing a large span between their contact points on the bore to be measured.

Anotherobject is to provide a gauge as set forth in the preceding objects wherein the locating pins are spring-urged in such `a manner as to be self-aligning relative to the bore, thereby automatically locating the measuring pins in coincidence with the diameter of the bore to be measured,

Another object is to provide a gauge fas set forth in the preceding objects wherein the dial indicator is mounted upon a structure which is swivelled relatively to the head containing the measuring pins so as to permit measurements to be taken in any direction of the bore while maintaining th'e dial indicator in clear view of the operator.

Other objects and advantages of the invention will become app-arent during the course of the Ifollowing description of the accompanying drawing, wherein:

Figure 1 is a side elevation of a preferred form of an internal bore dial indicator gauge according to the invention, with portions broken away to show the construction more clearly;

Figure 2 is a horizontal section along the line 2-2 in Figure 1;

Figure 3 is a vertical section along the line 3-3 in Figure 2; and

Figure 4 isa fragmentary vertical section Ialong the line 4--4 in Figure 1.

Referring to the drawing in detail, Figure 1 shows a preferred form of the internal bore dial indicator gauge of the invention as mounted on a head I which is in the form of a segment of a cylinder having la cavity I I of rectangular crosssection. A closure plate I2 slidable into the oppositely bevelled portions I3 closes the cavity II along the bottom thereof. The cavity II is sepa rated from the iiat rear face I4 of the h'ead I0 by a wall I5. The latter has a central threaded bore I6 for receiving the threaded end I1 of the fixed measuring pin I8, which is in the form of a thumbscrew with a. knurled portion I9 and a rounded end 2l). This construction enables measuring pins I8 of different lengths to be quickly and easily substituted for th'e pin shown, in order to adapt the device to bores 2| of diierent diameters.

The head Ill is lalso provided with a central bore 22 coaxial with the fixed measuring pin I8 and having an enlarged portion 23 therein (Figure 2). Reciprocably mounted in the bores 22 and 23 is a movable measuring pin 24 having a head 25 at its inner end engaging the bore 23, and la rounded end 26 engageable with the bore 2l to be measured. A plug 21 having a wedge portion 28 with an inclined surface 29 is secured in the inner end of the bore 23 and serves as an yabutmentA for a ball 38 which is disposed in the bore 23 and the inner surface 3l of the head 25 (Figure 3). The ball 30 also is engaged by the lower end 32 of a vertical plunger 33 mounted for reciprocation in a bore 34 extending into the bore 23 from a socket 35 in a boss 36 rising from the head Ill. Seated in the socket 35 is ,a tubular member 31 having an inner bore 38 spaced apart from but surrounding the plunger 33. Th'e tubular member 31 is secured in the socket 35 by a set screw 39 threaded into the screw hole 40 (Figure 3) and. groove 31a for Swiveling.

The upper end of the tubular member 31 is: firmly secured in any suitable way in a socket. 4I in an elbow 42, the rod 33 passing throughi a bore 43 therein into a cavity 44. The upper end 45 of the plunger 33 engages a projection 46 on;

the end of. 'a ro-d or shaft 41 rotatably mounted, in the bore 48 of the elbow 42. The projection 45: has a substantially flat sur-face 49 where it is engaged by the plunger 33.

Coaxial with the bore 48 is a socket 58 (Figure 1) serving` as a seat for the end of a tube 5I having an internal bore 52 surrounding but spaced apart from the shaft 41 and seated at its opposite end in a similar socket 53 in a handle 54. The shaft 41 at its opposite end passes through a bore 55 into a cavity 56 in the handle 54 and is provided at its end with a projection 51 similar to the projection 46 and having an upper surface 58 engaging the lower end 59 of the head so of a plunger 6| reciprocable vertically in a bore 62. The plunger El is surrounded by a coil spring 63 urging the plunger 6l downwardly.

The plunger 6| passes through a bore 64 in the stem 65 of a dial indicator 66 secured in the upper end of the bore 62. 'I'h'e dial indicator 66 (Figure 1) is of a conventional pattern whose details are well-known and in themselves form no part of the present invention. 'The dial indicator 56 is provided with a needle 61 connected by conventional mechanism to the plunger Bl and registering with a graduated circular scale 68 to indicate any suitable dimension such as thousandths of an inch. The handle 54 is provided withforward and rearward surfaces 69 and 'ID congured for convenience of grasping between the zpal'm and ngers of one hand, the handle 54 being cut away as at 1| and 'l2 to further facilitate such grasping. t

The head I6 is provided with a pair-of bores '-73 (Figure 2) having their axes larranged atanA acute angle. The bores I3 serve toreceivethe reciprocable locating pins lf3 having rounded outer'ends '75 and inner ends 'It provided with threaded Asockets Tl. Threaded into the sockets H are studs `'t8 having Vheads I9. Coitsprings are .mounted between the heads 19 "and plugs 3l which close the inner ends of the bores 7g3 and lwhich have bores82 through which the Shanksof fthe studs18 freelypass.Y Y .Y

Thepins 'id are notched as at 8,3 to receiiejthe lends 84 of pins 85 which are reciprocablejnbores B6 Whose axes are parallel with the axis of the ybore 22, vThe loins,Y 85 areinterconnedted by a cross bar 3'! secured thereto bythe set vscrews :88 threadedir'itov the sockets 8f3 in the ends .thereof. The cross'bar 8l is providedl withapertures Se for the free passage of the heads l'iS of thev studs ive. con springend; molunted between the cross bar 8i and plugs-'92 threaded intothelb'res 93 in the Wall l5 serve to urge the pins 85V into engagement' with the notches `8,3. The, coil springsV El are considerably Stronger rthan the coil springs 8e and hence overpower the latter so as toV urge the 85 and 'M' outwardly, thereby causing the curved; ends 1 5, ofthe pins 'ifi to come into engagement'w-ith the bore/Zlbeing measured. The weaker coil springs 80:.serve to maintain the forward Walls. 9c ofthenotches 83 in engagement with the ends 84 ofithe pins 85'.

Inithe operation of the inventionL thevproper length .of fixed measuring pin i8 is rst; chosen and screwed into the bore VI'B. The gaugeis then grasped in the hand of the user by means "of the handle ft and the lower portion thereof contain-- ing the head I8 and its associated parts pushed downwardly into the` bore 2|L to; be-measurjed`.j As theY locatingV pins 'M enter the bore Zt', 'their curved endsL 15, urged by the pins djarrdf coil springs 9| engaging the notches 33, adust themselves tothe bore 2i so that the axis'oijtlfre'meas urin'g pins24 and i8 isi-broughtintocoincidence with the diameter of the bore-21l Y While this is occurring, the movable measurthe wedge portion 28 Ion the plug 215,' causingfthe plunger 33 tol be moved? upwardlyfThe-upper Y end' of the upwardly-movingplunger 343i then-engages the projection Li' onlthe endl ofthe-shaft d?, rotating the latter andi causing thepro'ection 5t tol-ift theplungeril! and s'.'w -g-the 'needle 6,1 O'fV theV dialv indicator S5' unti-l it cornes toires't opposite. onefof VVthe* g'raduaitions568.` 'Thedimension may then be read directly oil the dial indicator 66.

When the measurement is observed and, if desired, recorded, the head I0 and its associated parts are lifted out of the bore 2|. The coil spring 63 then urges the plunger 6| Vdownwardly and the foregoing movements of the shaft 41, plunger 33, ball 30 and pin 24 are reversed, causing the pin 2L! tomove outwardly from the head l0. v

By the present invention, therefore, there has been provided an internal bore dial indicator gauge which is instantly adaptable to any diameter within the range of the instrument, and which ,is extremely accurate. The various moving parts ends 'i5 thereof, yet are housed in a relatively Y compact head la. lThese automatically urgethe measuring pins `itl andd into coincidence vwith the diameter of the bore 2l, Fixed measuring pins i3 of various lengths may be provided insets so that `the properi-lxed Ypin |78 can be Yquickly selected and screwed into the threa'dedpbore :I6 ofthe khead le, which is 'also swiveled on the tube While I have shown and described myinvention in detail, it is to be understood that Vthesame is tobe limited vonly bythe appended claims, for many changes maybe "made without departing from the spirit `andY scope of myinvention.

What I claim is: g l. In a gauge, a head, a stationary measuring pin anda movable measuring pin mounted jin alignment inesaidxhead, `agpair of locating -pins arranged .at an acute angle on opposite sideso'f said movable measuring pin, a measurementindicator operatively connected to said movable measuring pin,

2. In a gauge, a head, a stationary measuring pin and a movable measuring pin mounted in alignment in said head,:a 4pair of movable locating pins arranged at an acute angle on` oppo-V site sides yof said movable -measuring pin;V ka measurement A indcator'roper'atively connected. to saidmovable measuring pin,a pair ofV springloaded plungers mounted insaid headwithltheir outer Vends obliquely engaging and kurging said locatingY `pins outwardly relatively to said head, and a cross-nember securedto and interconnecting the inner ends of said plungers. n e

3. In a gauge, a head, a stationary measuring pin 'and @movable measuring p'i'n' mounted-.in alignment in said head, a hair of Inovablelo cating pins' arranged at an acute angle. oil-dbp6,- site sides .of said movable measuring pin, a measurement indicator operatively .oorieicted to said movable measuring pin, and a` pairofisprinloaded plungers mounted in s aidheadwitlflthi'r axes substantially `parallel toV the 'axis o said movable pin `and vengaging and urgnggsadiljo'cat. ingA pins outwardly relatively to saidJhead.

4; In a gauge, Va. head', astationaryine'suring pin anda movable measuring'jy pingniountedin alignment inl saidhead', a afOfmOl/ble 'QtCed locatingy pins arrangedv at an 'acutejaleon oppos'i-te'tsidesjV of' said movable' Vrneasuri'rig pinta measurement indicator operatively: connected toY saidn'iovable measuring-@mand af pair of signingA loaded piungers mounted in saidfheaa omiquei'y anda pair of spring-loaded Vplungers mounted in said head androbliquely en- Y fy 5 6 to said locating pins with their outer ends en- UNITED STATES PATENTS gaging said notches and urging said locating pins outwardly relatively to said head. Number Name Date 1,373,319 Ferrand Mar. 29, 1921 ANDREW EISELE 1,420,951 Bartholdy June 27, 1922 1,431,613 Wittner A Oct, 10, 1922 REFERENCES CITED 1,671,168 Steinle May 29, 1928 `2,095,405 Adelborgh et al. Oct. 12, 1937 The following references are of record in the 2,268,579 Eisele Jan. 6, 1942 iile of this patent: 10 2,385,122 Worthen Sept. 18, 1945 

